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  • 1.
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Methodological aspects on microdialysis sampling and measurements2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background:     The microdialysis (MD) technique is widely spread and used both experi­mentally and in clinical practice. The MD technique allows continuous collection of small molecules such as glucose, lactate, pyruvate and glycerol. Samples are often analysed using the CMA 600 analyser, an enzymatic and colorimetric analyser.  Data evaluating the performance of the CMA 600 analysis system and associated sample han­dling are sparse. The aim of this work was to identify sources of variability related to han­dling of microdialysis samples and sources of error associated with use of the CMA 600 analyser. Further, to develop and compare different application techniques of the micro­dialysis probes both within an organ and on the surface of an organ.

     Material and Methods:  Papers I and II are mainly in vitro studies with the exception of the No Net Flux calibration method in paper I where a pig model (n=7) was used to exam­ine the true concen­tration of glucose and urea in subcutaneous tissue. Flow rate, sampling time, vial and caps material and performance of the analyser device (CMA 600) were examined. In papers III and IV normoventilated anaesthetised pigs (n=33) were used. In paper III, heart ischemia was used as intervention to compare microdialysis measurements in the myocardium with corresponding measurements on the heart surface. In paper IV, microdialysis measurements in the liver parenchyma were compared with measurements on the liver surface in associa­tion with induced liver ischemia. All animal studies were approved by the Animal Experi­mental Ethics Committee at Umeå University Sweden.

    Results:  In paper I we succeeded to measure true concentrations of glucose (4.4 mmol/L) and Urea (4.1 mmol/L) in subcutaneous tissue. Paper II showed that for a batch analyse of 24 samples it is preferred to store microdialysis samples in glass vials with crimp caps. For reliable results, samples should be centrifuged before analysis. Paper III showed a new application area for microdialysis sampling from the heart, i.e. surface sampling. The sur­face probe and myocardial probe (in the myocardium) showed a similar pattern for glucose, lactate and glycerol during baseline, short ischemic and long ischemic interventions. In paper IV, a similar pattern was observed as in paper III, i.e. data obtained from the probe on the liver surface showed no differences compared with data from the probe in liver paren­chyma for glucose, lactate and glycerol concentrations during baseline, ischemic and reperfusion interven­tions.

    Conclusion:  The MD technique is adequate for local metabolic monitoring, but requires methodological considerations before starting a new experimental serie. It is important to consider factors such as flow rate, sampling time and handling of samples in association with the analysis device chosen. The main finding in this thesis is that analyses of glucose, lactate and glycerol in samples from the heart surface and liver surface reflect concentra­tions sampled from the myocardium and liver parenchyma, respectively.

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  • 2.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Optimised sample handling in association with use of the CMA 600 analyser2008In: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 48, no 5, p. 940-945Article in journal (Refereed)
    Abstract [en]

    A large degree of variability for batched analysis of serially collected microdialysis samples measured with the CMA 600 analyser has been described. This study was designed to identify sources of variability related to sample handling. Standard concentrations of four solutes were placed in microdialysis vials and then stored and analysed at intervals. Results were analysed for variability related to vial and cap type, duration and temperature of storage, centrifugation and re-analysis. The main results were that centrifugation of samples reduced variability. When a batch of 24 samples was analysed, the use of crimp caps reduced evaporation. Samples in glass vials with crimp caps could be stored in a refrigerator for up to 14 days without large variability in concentration compared to plastic vials which demonstrated variability already when stored for more than 1 day. We conclude that variability in microdialysis results can occur in relation to storage and analysis routines if routines are not optimised concerning evaporation. Centrifugation before analyses, glass vials with crimp caps even during frozen storage, and attention to minimal times for samples to be uncapped during analysis all contribute to minimise variability in the handling and analysis of microdialysis samples.

  • 3.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, Per Jonas
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Outcome of microdialysis sampling on liver surface and parenchyma2016In: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 200, no 2, p. 480-487Article in journal (Refereed)
    Abstract [en]

    Background: To investigate whether surface microdialysis (μD) sampling in probes covered by a plastic film, as compared to noncovered and to intraparenchymatous probes, would increase the technique's sensitivity for pathophysiologic events occurring in a liver ischemia-reperfusion model. Placement of μD probes in the parenchyma of an organ, as is conventionally done, may cause adverse effects, e.g., bleeding, possibly influencing outcome.

    Methods: A transient ischemia-reperfusion model of the liver was used in six anesthetized normoventilated pigs. μD probes were placed in the parenchyma and on the liver surface. Surface probes were either left uncovered or were covered by plastic film.

    Results: Lactate and glucose levels were significantly higher in plastic film covered probes than in uncovered surface probes throughout the ischemic period. Glycerol levels were significantly higher in plastic film covered probes than in uncovered surface probes at 30 and 45 min into ischemia.

    Conclusions: Covering the μD probe increases the sensibility of the μD–technique in monitoring an ischemic insult and reperfusion in the liver. These findings confirm that the principle of surface μD works, possibly replacing need of intraparenchymatous placement of μD probes. Surface μD seemingly allows, noninvasively from an organ's surface, via the extracellular compartment, assessment of intracellular metabolic events. The finding that covered surface μD probes allows detection of local metabolic changes earlier than do intraparenchymatous probes, merit further investigation focusing on μD probe design.

  • 4.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    An assessment of calibration and performance of the microdialysis system2005In: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 39, no 3-4, p. 730-734Article in journal (Refereed)
    Abstract [en]

    To improve the reliability of microdialysis measurements of tissue concentrations of metabolic substances, this study was designed to test both the performance and the internal validity of the microdialysis methods in the hands of our research group. The stability of the CMA 600 analyser was tested with a known glucose solution in 72 standard microvials and in 48 plastic vials. To evaluate if variation in sampling time makes any difference in sample concentration (recovery), sampling times of 10, 20 and 30 min were compared in vitro with a constant flow rate of 1 microl/min. For testing of sampling times at different flow rates, an in vitro study was performed in which a constant sample volume of 10 microl was obtained. With the no net flux method, the actual concentration of glucose and urea in subcutaneous tissue was measured. The CMA 600 glucose analysis function was accurate and stable with a coefficient of variability (CV) of 0.2-0.55%. There was no difference in recovery for the CMA 60 catheter for glucose when sampling times were varied. Higher flow rates resulted in decreased recovery. Subcutaneous tissue concentrations of glucose and urea were 4.4 mmol/l and 4.1 mmol/l, respectively. To conclude, this work describes an internal validation of our use of the microdialysis system by calibration of vials and catheters. Internal validation is necessary in order to be certain of adequate sampling times, flow rates and sampling volumes. With this in mind, the microdialysis technique is useful and appropriate for in vivo studies on tissue metabolism.

  • 5.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Detection of myocardial ischaemia using surface microdialysis on the beating heart2011In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, no 3, p. 175-181Article in journal (Refereed)
    Abstract [en]

    Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

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  • 6.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, Per-Jonas
    Kirurgi, Skåne Universitets sjukhus, Lund.
    Comparison between outcome of  surface and intraparenchymatous sampling using microdialysis in an experimental liver ischemia modelManuscript (preprint) (Other academic)
    Abstract [en]

    Introduction. We recently have shown that samples from MD probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces.

    Material and methods.  In thirteen anesthetized pigs transient liver ischemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface, and two in parenchyma were perfused with a flow rate of 1 µL/min (n=13). An identical set up was used for probes with a flow rate of 2 µL/min (n=9). Samples were collected for every 15 minute period during 60 minutes of baseline, 45 minutes of ischemia and 60 minutes of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present paper.

    Results. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and parenchyma. No significant differences in relative changes of lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischemia or reperfusion with a flow rate of 1 µL/min.

    Conclusion. MD sampling applied on the liver surface is a new application area for the MD technique, and may be used to monitor liver metabolism both during physiological and pathophysiological conditions.

  • 7.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, Per-Jonas
    Surface microdialysis sampling: a new approach described in a liver ischaemia model2012In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, no 2, p. 99-105Article in journal (Refereed)
    Abstract [en]

    We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 mu l per min (n = 13). An identical set-up was used for probes with a flow rate of 2 mu l per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 mu l per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions.

  • 8.
    af Klinteberg, Ingvar
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Airway management and safety aspects during induction of anaesthesia. - A comparison between Rapid sequence induction and Target controlled infusion in non-cardiac surgery2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 9.
    Ahlberg, Hans
    et al.
    Department of Surgical and Perioperative Sciences, Anaesthesiology and Intensive Care Medicine (Östersund).
    Wallgren, Daniel
    Department of Surgical and € Perioperative Sciences, Anaesthesiology and Intensive Care Medicine (Sunderbyn).
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Department of Surgical and € Perioperative Sciences, Anaesthesiology and Intensive Care Medicine (Sunderbyn).
    Johansson, Joakim
    Department of Surgical and Perioperative Sciences, Anaesthesiology and Intensive Care Medicine (Östersund).
    Less use of rescue morphine when a combined PSP/IPP-block is used for postoperative analgesia in breast cancer surgery: A randomised controlled trial2023In: European Journal of Anaesthesiology, ISSN 0265-0215, E-ISSN 1365-2346, Vol. 40, no 9, p. 636-642Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Surgery for breast cancer is common, and intravenous opioids are often used to control postoperative pain. Recently, pectoralis-2 (PECS-2) block has emerged as a promising regional anaesthetic alternative. With nomenclature recently proposed, this block is termed combined PSP/IPP-block (pectoserratus plane block/interpectoral plane block).

    OBJECTIVE: We aimed to compare the need for postoperative rescue morphine between the intervention group that received a pre-operative combined PSP/IPP-block and a control group that received peri-operative long-acting opioids for postoperative analgesia.

    DESIGN: A randomised controlled study.

    SETTING: Operating theatres of two Swedish hospitals. The patients were recruited between May 2017 and October 2020.

    PATIENTS: Among the 199 women scheduled to undergo breast cancer surgery (sector resection or radical mastectomy) who were enrolled in the study, 185 were available for follow up.

    INTERVENTION: All patients received general anaesthesia. The intervention group received a combined PSP/IPP-block before surgery. The control group received intravenous morphine 30 min before emergence from anaesthesia.

    MAIN OUTCOME MEASURE: The primary endpoint was the cumulative need for intravenous rescue morphine to reach a predefined level of pain control (visual analogue scale score <40 mm) during the first 48 h after surgery.

    RESULTS: Data from 92 and 93 patients in the intervention and control groups, respectively, were analysed. The amount of rescue morphine administered in the 48 h after surgery was significantly lower in the intervention group than in the control group (median: 2.25 vs 3.0 mg, P  = 0.021). The first measured pain score was lower in the intervention group than in the control group (35 vs. 40 mm, P  = 0.035). There was no significant difference in the incidence of nausea between the groups (8.7 vs. 12.9%, P  = 0.357).

    CONCLUSION: The use of a combined PSP/IPP-block block before breast cancer surgery reduces the need for postoperative rescue morphine, even when compared with the use of intra-operative morphine.

    TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT03117894.

  • 10.
    Ahlström, Katarina
    et al.
    Anesthesia and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Biber, Björn
    Anesthesia and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Ronquist, Gunnar
    Department of Medical Chemistry, Uppsala University, Uppsala, Sweden.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Haney, Michael F.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Exogenous carbon monoxide does not affect cell membrane energy availability assessed by sarcolemmal calcium fluxes during myocardial ischaemia-reperfusion in the pig2011In: European Journal of Anaesthesiology, ISSN 0265-0215, E-ISSN 1365-2346, Vol. 28, no 5, p. 356-362Article in journal (Refereed)
    Abstract [en]

    Carbon monoxide is thought to be cytoprotective and may hold therapeutic promise for mitigating ischaemic injury. The purpose of this study was to test low-dose carbon monoxide for protective effects in a porcine model of acute myocardial ischaemia and reperfusion.

    In acute open-thorax experiments in anaesthetised pigs, pretreatment with low-dose carbon monoxide (5% increase in carboxyhaemoglobin) was conducted for 120 min before localised ischaemia (45 min) and reperfusion (60 min) was performed using a coronary snare. Metabolic and injury markers were collected by microdialysis sampling in the ventricular wall. Recovery of radio-marked calcium delivered locally by microperfusate was measured to assess carbon monoxide treatment effects during ischaemia/reperfusion on the intracellular calcium pool.

    Coronary occlusion and ischaemia/reperfusion were analysed for 16 animals (eight in each group). Changes in glucose, lactate and pyruvate from the ischaemic area were observed during ischaemia and reperfusion interventions, though there was no difference between carbon monoxide-treated and control groups during ischaemia or reperfusion. Similar results were observed for glycerol and microdialysate Ca recovery.

    These findings show that a relatively low and clinically relevant dose of carbon monoxide did not seem to provide acute protection as indicated by metabolic, energy-related and injury markers in a porcine myocardial ischaemia/reperfusion experimental model. We conclude that protective effects of carbon monoxide related to ischaemia/reperfusion either require higher doses of carbon monoxide or occur later after reperfusion than the immediate time frame studied here. More study is needed to characterise the mechanism and time frame of carbon monoxide-related cytoprotection.

  • 11.
    Ahlström, Katarina
    et al.
    Anestesi, Sahlgrenska akademin, Göteborgs universitet.
    Biber, Björn
    Anestesi, Sahlgrenska akademin, Göteborgs universitet.
    Åberg, Annamaja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Ronquist, Gunnar
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Strandén, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Metabolic responses in ischemic myocardium after inhalation of carbon monoxide2009In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 53, no 8, p. 1036-1042Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: To clarify the mechanisms of carbon monoxide (CO) tissue-protective effects, we studied energy metabolism in an animal model of acute coronary occlusion and pre-treatment with CO. METHODS: In anesthetized pigs, a coronary snare and microdialysis probes were placed. CO (carboxyhemoglobin 5%) was inhaled for 200 min in test animals, followed by 40 min of coronary occlusion. Microdialysate was analyzed for lactate and glucose, and myocardial tissue samples were analyzed for adenosine tri-phosphate, adenosine di-phosphate, and adenosine mono-phosphate. RESULTS: Lactate during coronary occlusion was approximately half as high in CO pre-treated animals and glucose levels decreased to a much lesser degree during ischemia. Energy charge was no different between groups. CONCLUSIONS: CO in the low-doses tested in this model results in a more favorable energy metabolic condition in that glycolysis is decreased in spite of maintained energy charge. Further work is warranted to clarify the possible mechanistic role of energy metabolism for CO protection.

  • 12.
    Alfraeus, Simon
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hypotensive Effect of Anesthesia with Target controlled infusion: A randomized controlled trial2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 13.
    Allvin, Renée
    et al.
    Clinical Skills Centre, Faculty of Medicine and Health, School of Medical Sciences, Örebro University, Örebro.
    Berndtzon, Magnus
    Metodikum – Skill Centre of Medical Simulation Region County Jönköping, Jönköping.
    Carlzon, Liisa
    Simulation Centre West, Department of Research, Education and Development, Sahlgrenska University Hospital, Gothenburg.
    Edelbring, Samuel
    Department of Medical and Health Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping.
    Hult, Håkan
    Department of Medical and Health Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Karlgren, Klas
    Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm.
    Masiello, Italo
    Department of Clinical Science and Education, Karolinska Institutet, Södersjukhuset Hospital, Stockholm.
    Södersved Källestedt, Marie-Louise
    Clinical Skills Centre, Centre for Clinical Research, Uppsala University, Västerås.
    Tamás, Éva
    Department of Cardiovascular Diseases, Institute of Medicine and Health, Medical Faculty, University of Linköping, Linköping.
    Confident but not theoretically grounded: experienced simulation educators’ perceptions of their own professional development2017In: Advances in Medical Education and Practice, E-ISSN 1179-7258, no 8, p. 99-108Article in journal (Refereed)
    Abstract [en]

    Background: Medical simulation enables the design of learning activities for competency areas (eg, communication and leadership) identi ed as crucial for future health care professionals. Simulation educators and medical teachers follow different career paths, and their education backgrounds and teaching contexts may be very different in a simulation setting. Although they have a key role in facilitating learning, information on the continuing professional development (pedagogical development) of simulation educators is not available in the literature. Objectives: To explore changes in experienced simulation educators’ perceptions of their own teaching skills, practices, and understanding of teaching over time.

    Methods: A qualitative exploratory study. Fourteen experienced simulation educators partici- pated in individual open-ended interviews focusing on their development as simulation educators. Data were analyzed using an inductive thematic analysis. Results: Marked educator development was discerned over time, expressed mainly in an altered way of thinking and acting. Five themes were identi ed: shifting focus, from following to utilizing a structure, setting goals, application of technology, and alignment with profession. Being con dent in the role as an instructor seemed to constitute a foundation for the instructor’s pedagogical development.

    Conclusion: Experienced simulation educators’ pedagogical development was based on self- con dence in the educator role, and not on a deeper theoretical understanding of teaching and learning. This is the rst clue to gain increased understanding regarding educational level and possible education needs among simulation educators, and it might generate several lines of research for further studies. 

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  • 14.
    Alth, Ellen
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Nutrition av IVA-patienter vid hemodynamisk instabilitet2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 15. Anderson, M
    et al.
    Domellöf, L
    Eksborg, S
    Häggmark, S
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, G
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Reiz, S
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Herslöf, Å
    Pharmacokinetics and Central Haemodynamic Effects of Doxorubicin and 4'Epi-Doxorubicin in the Pig1989In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 28, no 5, p. 709-714Article in journal (Refereed)
  • 16.
    Andersson, Clara
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Symtom, hälsorelaterad livskvalitet och fysisk kapacitet 1 år efter covid-192022Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 17.
    Andersson, Isaac
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Intensivvårdskrävande COVID-19-patienter i en regional kohort i Sverige – nutritionsaspekter.2022Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 18.
    Andersson, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Wennberg, Patrik
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Rolandsson, Olov
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Att skapa läkare i glesbygd2018In: Allmänmedicin : tidskrift för Svensk förening för allmänmedicin, ISSN 0281-3513, no 3, p. 26-27Article in journal (Other (popular science, discussion, etc.))
  • 19.
    Andersson, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sjöström, Lars-Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Karpe, Fredrik
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Dysregulation of subcutaneous adipose tissue blood flow in overweight postmenopausal women2010In: Menopause: The Journal of the North American Menopause, ISSN 1072-3714, E-ISSN 1530-0374, Vol. 17, no 2, p. 365-371Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: A putative link between abdominal obesity and metabolic-vascular complications after menopause may be due to a decreased adipose tissue blood flow (ATBF). The present work aimed to analyze possible changes in ATBF with being overweight and menopausal and its putative link to endothelial dysfunction and autonomic nervous system balance.

    METHODS: Forty-three healthy women were classified into four groups according to weight and menopause status. The ATBF was measured by xenon washout while fasting and after oral glucose intake. The nitric oxide synthase inhibitor asymmetric dimethylarginine was used as a marker of endothelial function and heart rate variability-estimated autonomic nervous system activity.

    RESULTS: Fasting ATBF was decreased in both overweight groups (P = 0.044 and P = 0.048) versus normal-weight premenopausal women. Normal-weight and overweight postmenopausal women exhibited lower maximum ATBF compared with normal-weight premenopausal women (P = 0.015 and P = 0.001, respectively), and overweight postmenopausal women exhibited lower maximum ATBF compared with normal-weight postmenopausal women (P = 0.003). A negative correlation was found between fasting ATBF and asymmetric dimethylarginine (P = 0.015), whereas maximum ATBF was negatively associated with sympathetic-parasympathetic nervous system balance (ratio of the power of the low frequency to the power of the high frequency; P = 0.002).

    CONCLUSIONS: Loss of ATBF flexibility in overweight postmenopausal women may contribute to the metabolic dysfunction seen in this group of women.

  • 20.
    Andersson, Magnus
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Domellöf, Lennart
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Häggmark, Sören
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Reiz, Sebastian
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustavsson, Bengt
    Cardiopulmonary hemodynamics and pharmacokinetics after hepatic intraarterial infusion of 5-fluorouracil (5-FU)1988In: Cancer Chemotherapy and Pharmacology, ISSN 0344-5704, E-ISSN 1432-0843, Vol. 22, no 3, p. 251-255Article in journal (Refereed)
  • 21.
    Andersson, Nina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Grip, Helena
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Lindvall, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Koskinen, Lars-Owe D
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Brändström, Helge
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Air transport of patients with intracranial air: computer model of pressure effects2003In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 74, no 2, p. 138-144Article in journal (Refereed)
  • 22.
    Andersson-Wenckert, Ingrid
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Häggmark, Sören
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lindkvist, Robert
    Reiz, Sebastian
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Anevac-D, a new system for close scavenging of anesthetic gases in dental practice1989In: Scandinavian Journal of Dental Research, ISSN 0029-845X, Vol. 97, no 5, p. 456-64Article in journal (Refereed)
    Abstract [en]

    Anevac-D, a new system for close scavenging of anesthetic gases in dental practice is described. It consists of a rubber nose mask surrounded by an outer rigid shell and a chin scavenger. A vacuum in the slot between the nose masks provides scavenging of gases escaping from the inner mask. Gases escaping from the mouth are evacuated mainly by the skin scavenger. The efficiency of this system was assessed in healthy volunteers using argon as a tracer gas. Mass spectrometry was used for measurement of inspired, expired, and scavenged gas concentrations. The scavenging efficiency of the complete system was around 80% and was not affected by poor patient cooperation. It decreased to about 65% when the chin scavenger was removed. The dentist's exposure was measured by sampling of argon in the breathing zone by a Saran system. The average 4-min exposure varied between 90 and 250 ppm depending on system configuration and patient cooperation. Patient acceptance and clinical applicability were judged good. It is concluded that the Anevac-D system provides excellent scavenging properties and exposure levels well within the official recommendations by the Swedish Board of Occupational Safety and Health.

  • 23.
    A'roch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular function's relation to load, experimental studies in a porcine model2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Loading conditions are recognized to influence ventricular function according to the Starling relationship for length/stretch and force.  Many modern echocardiographic parameters which have been announced as describing ventricular function and contractile status, may be confounded by uncontrolled and unmeasured load.  These studies aimed to measure the relation between four differ­ent types of assessments of ventricular dysfunction and degrees of load.  Study examined the ‘myo­cardial performance index’ (MPI).  Study II examined long axis segmental mechanical dyssynchrony.  Study III examined tissue velocities, and Study IV examined ventricular twist.  All studies aimed to describe the relation of these parameters both to load and to inotropic changes.

    Methods:  In anesthetized juvenile pigs, left ventricular (LV) pressure and volume were measured continuously and their relationship (LVPVR) was analysed.  Preload alterations were brought about by inflation of a balloon tipped catheter in the inferior vena cava (IVCBO).  Inotropic interventions were brought about by either an overdose of anesthetic (combine intravenous pentobarbital and inhaled isoflurane, Study I), or beta blocker and calcium channel blocker given in combination (Stud­ies III and IV).  In one study (II), global myocardial injury and dysfunction was induced by endotoxin infusion.  MPI measurements were derived from LVPVR heart cycle intervals for isovolumic contrac­tion and relaxation as well as ejection time.  Long axis segmental dyssynchrony was derived by ana­lyzing for internal flow and time with segmental dyssynchronous segment volume change during systole, hourly before and during 3 hours of endotoxin infusion.  Myocardial tissue velocities were measured during IVCBO at control, during positive and then later negative inotropic interventions.  The same for apical and base circumferential rotational velocities by speckle tracking.  Load markers (including end-diastolic volume) were identified for each beat, and the test parameters were analysed together with load for a relation.  The test parameters were also tested during single apneic beats for a relation to inotropic interventions.

    Results: MPI demonstrated a strong and linear relationship to both preload and after-load, and this was due to changes in ejection time, and not the isovolumic intervals.  Long axis segmental dyssyn­chrony increased during each hour of endotoxin infusion and global myocardial injury.  This dysyn­chrony parameter was independent of load when tested by IVCBO. Peak systolic velocities were strongly load-independent, though not in all the inotropic situations and by all measurement axes.  Peak systolic strain was load-dependent, and not strongly related to inotropic conditions.  Peak sys­tolic LV twist and untwist were strongly load-dependent.

    Conclusions: MPI is strongly load-dependent, and can vary widely in value for the same contractile status if the load is varied.  Mechanical dyssynchrony measures are load-independen in health and also in early global endotoxin myocardial injury and dysfunction.  Peak sytole velocities are a clinically robust parameter of LV regional and global performance under changing load, though peak systolic strain seems to be load-dependent.  Left ventricular twist and untwist are load-dependent in this pig model.

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  • 24.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model2012In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 10, no 1, article id 22Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function. Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility, though their load-sensitivity has been studied in different settings, but still remains a matter of controversy. We sought to characterize the effects of acute load change (both preload and afterload) and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility.

    METHODS: Thirteen anesthetized juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled load alterations. At least eight consecutive beats in the sequence were analyzed with tissue velocity echocardiography during the load alteration and analyzed for change in peak systolic velocities and strain during same contractile status with a controlled load alteration. Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    RESULTS: Peak systolic velocities reflected the drug-induced changes in contractility in both radial and longitudinal axis. During the acute load change, the peak systolic velocities remain stable when derived from signal in the longitudinal axis and from the radial axis. The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied (peak systolic velocity, longitudinal axis, control group beat 1- 5.72 +/- 1.36 with beat 8- 6.49 +/- 1.28 cm/sec, 95% confidence interval), with the single exception of the negative inotropic intervention group where peak systolic velocity decreased a small amount during load reduction (beat 1- 3.98 +/- 0.92 with beat 8- 2.72 +/- 0.89 cm/sec). Systolic strain, however, showed a clear degree of load-dependence.

    CONCLUSIONS: Peak systolic velocity appears to be load-independent as tested by beat-to-beat load reduction, while peak systolic strain appears to be load-dependent in this model. Peak systolic velocity, in a controlled experimental model where successive beats during load alteration are assessed, has a strong relation to contractility. Peak systolic velocity, but not peak strain rate, is largely independent of load, in this model. More study is needed to confirm this finding in the clinical setting.

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  • 25.
    A'roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Strain and peak systolic velocities: relation to load in a porcine modelManuscript (preprint) (Other academic)
    Abstract [en]

    Background:  Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function.  Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility.  Their load-sensitivity has been studied in different settings, but still remains a matter of controversy.  We sought to characterize the effects of acute load change and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility, and particularly to determine if these parameters were load-dependent.

    Methods: Thirteen anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled preload alterations.  At least eight consecutive beats in the preload alteration sequence were analysed with tissue velocity echocardiography (TVE) during the preload alteration and analysed for change in peak systolic velocities (PSV) and strain (e) during same contractile status with a controlled preload alteration.  Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    Results: PSV reflected the drug-induced changes in contractility in both radial and longitudinal axis.  During the acute load change, the PSV remain stable when derived from signal in the longitudinal axis and from the radial axis.  The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied.  Peak systolic strain, however, showed a clear degree of load-dependence.

    Conclusion:  Peak systolic velocity appears to be load-independent as tested by beat to beat load reduction, while peak systolic strain appears to be load-dependent in this model.  Peak systolic velocity has a strong relation to contractility, independent of load, in serial measures, in this model.  More study is needed to confirm this in the clinical setting.

  • 26.
    A'roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular twist is load-dependentManuscript (preprint) (Other academic)
    Abstract [en]

    Background: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of LV contractility.

    Methods: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon catheter (IVCBO) produced controlled load reduction.  First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status.  Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal.

    Results: The IVCBO load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56° ±5.1° vs. 16.57° ±4.6° (p < 0.013), and though increased, didn’t reach significance in nega­tive inotropic condition.  Untwisting rate increased significantly at baseline from    -41.7°/sec ±41.6°/sec vs. -122.6°/sec ±55.8°/sec (P < 0.039) and under adrenaline stimulation untwisting rate increased  (-55.3°/sec ±3.8°/sec vs.  -111.4°/sec ±24.0°/sec (p<0.05), but did not systematically changed in negative inotropic condition.

    Conclusions: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent.  Changes in LV load should be considered when interpreting  LV rotation/ twist.

  • 27.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load2012In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 10, article id 26Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV) contractility.

    METHODS: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB) catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon's Signed Rank test.

    RESULTS: The inferior vena cava balloon occlusion (IVCBO) load change compared for first to last beat resulted in LV twist increase (11.67degrees +/-2.65degrees vs. 16.17degrees +/-3.56degrees respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56degrees +/-5.1degrees vs. 16.57degrees +/-4.6degrees (p < 0.013), and though increased, didn't reach significance in negative inotropic condition. Untwisting rate increased significantly at baseline from 41.7degrees/s +/-41.6degrees/s vs.122.6degrees/s +/-55.8degrees/s (P < 0.039) and under adrenaline stimulation untwisting rate increased (55.3degrees/s +/-3.8degrees/s vs.111.4degrees/s +/-24.0degrees/s (p < 0.05), but did not systematically changed in negative inotropic condition.

    CONCLUSIONS: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

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  • 28.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Steendijk, Paul
    Oldner, Anders
    Weitzberg, Eddie
    Konrad, David
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular mechanical dyssynchrony is load independent at rest and during endotoxaemia in a porcine model2009In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 196, no 4, p. 375-383Article in journal (Refereed)
    Abstract [en]

    AIM: In diseased or injured states, the left ventricle displays higher degrees of mechanical dyssynchrony. We aimed at assessing mechanical dyssynchrony ranges in health related to variation in load as well as during acute endotoxin-induced ventricular injury.

    METHODS: In 16 juvenile anaesthetized pigs, a five-segment conductance catheter was placed in the left ventricle as well as a balloon-tipped catheter in the inferior vena cava. Mechanical dyssynchrony during systole, including dyssynchrony time in per cent during systole and internal flow fraction during systole, were measured at rest and during controlled pre-load reduction sequences, as well as during 3 h of endotoxin infusion (0.25 microg kg(-)1 h(-1)).

    RESULTS: Systolic dyssynchrony and internal flow fraction did not change during the course of acute beat-to-beat pre-load alteration. Endotoxin-produced acute pulmonary hypertension by left ventricular dyssynchrony measures was not changed during the early peak of pulmonary hypertension. Endotoxin ventricular injury led to progressive increases in systolic mechanical segmental dyssynchrony (7.9 +/- 1.2-13.0 +/- 1.3%) and ventricular systolic internal flow fraction (7.1 +/- 2.4-16.6 +/- 2.8%), respectively for baseline and then at hour 3. There was no localization of dyssynchrony changes to segment or region in the ventricular long axis during endotoxin infusion.

    CONCLUSION: These results suggest that systolic mechanical dyssynchrony measures may be load independent in health and during acute global ventricular injury by endotoxin. More study is needed to validate ranges in health and disease for parameters of mechanical dyssynchrony.

  • 29.
    Atterhem, Veronica
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    The incidence of hemodynamic and respiratory adverse events in morbidly obese presenting for Bariatric surgery2018In: International Journal of Clinical Anesthesia and Research, Vol. 2, no 1, p. 009-017Article in journal (Refereed)
    Abstract [en]

    Context: Perioperative management of morbidly obese patients undergoing bariatric surgery is challenging. Lacking standardized perioperative protocols, complication rates may be high. This retrospective study aims to quantify the incidence of significant blood pressure decreases on induction of anesthesia and intraoperative hypoxemia, before implementation of a standardized protocol designed for bariatric surgery.

    Design: Retrospective, observational study.

    Setting: A 250-bed county hospital in northern Sweden.

    Subjects: 219 morbidly obese patients (body mass index > 35 kg/m2) who underwent bariatric surgery between 2003 and 2008.

    Main outcome measures: Incidence of systolic blood pressure (SAP) falls to less than 70% of the preoperative baseline during induction of anesthesia and incidence of perioperative hypoxemia.

    Results: The incidence of confirmed SAP falls to below 70% of baseline at induction of anesthesia was 56.2% (n = 123/219). This incidence rose with increasing age (p < 0.001) but not with body mass index (BMI). 3.7% (n = 8/219) of cases were marked as difficult intubations. A transient period of hypoxemia was observed in 6.8% (n = 15/219) and was more common with increasing BMI (p = 0.005). Fourteen different drug combinations were used in the study population. Of those administered an induction anesthetic drug, 72.6% (n = 159/193) were given an overdose when calculated by lean body weight, but this did not correlate significantly to SAP falls (p = 0.468).

    Conclusions: The incidence of a significant blood pressure fall upon induction of anesthesia was common. The incidence of airway and ventilation problems were low. Overdosing of anesthetics and excessive variation in applied anesthesia methods were found.

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  • 30.
    Axelsson, Birger
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Cardiac effects of non-adrenergic inotropic drugs: clinical and experimental studies2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Myocardial failure and dysfunction is not uncommon during critical illness and following cardiac surgery. For optimal treatment, a better understanding of the effects of inotropic drugs is needed. In this thesis, two non-adrenergic mediated inotropes, milrinone and levosimendan were studied in different models of myocardial dysfunction. The study aims were to assess the following: the effects of milrinone on blood flow in coronary artery bypass grafts during CABG surgery; the effects of milrinone on left ventricular diastolic function during post-ischaemic myocardial dysfunction; whether milrinone or levosimendan are protective or injurious during acute myocardial ischaemia, and if levosimendan potentiates myocardial function when added to milrinone in an experimental model of post-ischaemic (stunned) myocardium.

    Material and Methods: In Study I, 44 patients undergoing coronary artery bypass surgery(CABG) were included as subjects. Milrinone or saline was administrated in a single dose during cardio-pulmonary bypass (CPB) and coronary graft flow measurements were recorded after 10 and 30 min following CPB. In Study II; 24 patients undergoing CABG had estimations of peak ventricular filling rates made before and after CPB with administration of milrinone or saline as a single dose during CPB, performed by assessment of the rate of change in diastolic cross-sectional left ventricular area. In Study III, energy-metabolic effects of milrinone and levosimendan were measured in an anaesthetized porcine model during 45 minutes of regional myocardial ischemia. Microdialysis sampling of metabolites of local ischemic metabolism allowed assessment of glycolytic activity and the degree of myocardial calcium overload. In Study IV, in a porcine model of postischaemic myocardial stunning, ventricular pressure-volume relationships were analyzed when milrinone or a combination of milrinone and levosimendan were given together.

    Results: In Study I, there was a clear increase in non-sequential saphenous vein graft blood flow with milrinone at 10 minutes (64.5 ± 37.4 compared to placebo 43.6 ± 25.7 ml/min (mean ± SD).). A decreasing but still measureable flow increase was seen for milrinone at 30 minutes. In Study II, an increase in early left ventricular filling rate (ventricular cross-sectional area rate of change,dA/dt) was seen in the milrinone treated group. Pre-bypass milrinone group dA/dt 22.0 ± 9.5 changed to post-bypass values dA/dt 27.8 ± 11.5 cm2/sec). Placebo group pre-bypass dA/dt was 21.0 ± 8.7 and post-bypass 17.1 ± 7.1 cm2/sec. A milrinone effect was demonstrated in an adjusted regression model (p = 0.001). In Study III, neither milrinone nor levosimendan led to a change in energy-metabolic activity during ischemia as reflected by interstitial glucose, pyruvate, lactate orglycerol. Neither drug exacerbated the relative myocardial calcium overload during ischemia. In Study IV, milrinone improved active relaxation (tau) in post-ischemic stunned myocardium, but did not markedly improve systolic function by preload recruitable stroke work. Levosimendan added to milrinone showed minimal effect on active relaxation but a positive effect on systolic function in combination with milrinone.

    Conclusions: We conclude that milrinone treatment leads to an increase in blood flow in newly implanted coronary saphenous vein grafts, and improves ventricular relaxation post-cardiopulmonary bypass. Neither milrinone nor levosimendan, in this porcine model, negatively influence myocardial energy metabolism or calcium overload during acute ischaemia. Addition of levosimendan to milrinone treatment during post-ischaemic ventricular dysfunction may provide additive inotropic effects on systolic function but probably not for active relaxation.

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  • 31.
    Axelsson, Birger
    et al.
    Örebro University, Örebro, Sweden .
    Häggmark, Sören
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Svenmarker, Staffan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gupta, Anil
    Örebro University, Örebro, Sweden .
    Tyden, Hans
    Örebro University, Örebro, Sweden .
    Wouters, Patrick
    Ghent, Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Effects of Combined Milrinone and Levosimendan Treatment on Systolic and Diastolic Function During Postischemic Myocardial Dysfunction in a Porcine Model2016In: Journal of Cardiovascular Pharmacology and Therapeutics, ISSN 1074-2484, E-ISSN 1940-4034, Vol. 21, no 5, p. 495-503Article in journal (Refereed)
    Abstract [en]

    It is not known whether there are positive or negative interactions on ventricular function when a calcium-sensitizing inotrope is added to a phosphodiesterase inhibitor in the clinical setting of acute left ventricular (LV) dysfunction. We hypothesized that when levosimendan is added to milrinone treatment, there will be synergetic inotropic and lusitropic effects. This was tested in an anesthetized porcine postischemic global LV injury model, where ventricular pressures and volumes (conductance volumetry) were measured. A global ischemic injury was induced by repetitive left main stem coronary artery occlusions. Load-independent indices of LV function were assessed before and after ventricular injury, after milrinone treatment, and finally after addition of levosimendan to the milrinone treatment. Nonparametric, within-group comparisons were made. The protocol was completed in 12 pigs, 7 of which received the inotrope treatment and 5 of which served as controls. Milrinone led to positive lusitropic effects seen by improvement in tau after myocardial stunning. The addition of levosimendan to milrinone further increased lusitropic state. The latter effect could however not be attributed solely to levosimendan, since lusitropic state also improved spontaneously in time-matched controls at the same rate during the corresponding period. When levosimendan was added to milrinone infusion, there was no increase in systolic function (preload recruitable stroke work) compared to milrinone treatment alone. We conclude that in this model of postischemic LV dysfunction, there appears to be no clear improvement in systolic or diastolic function after addition of levosimendan to established milrinone treatment but also no negative effects of levosimendan in this context.

  • 32.
    Axelsson, Birger
    et al.
    Dept of Cardiovascular and Thoracic Surgery and Anesthesiology and Intensive Care, Örebro University Hospital.
    Häggmark, Sören
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Svenmarker, Staffan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gupta, Anil
    Dept of Clinical Medicine, School of Health and Medical Sciences, Örebro University.
    Tydén, Hans
    Dept of Clinical Medicine, School of Health and Medical Sciences, Örebro University.
    Wouters, Patrick
    Dept of Anesthesiology, University Hospital Ghent, Ghent, Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Systolic and diastolic effects of milrinone and levosimendan in porcine post-ischemic myocardial dysfunctionManuscript (preprint) (Other academic)
  • 33.
    Axelsson, Birger
    et al.
    Dept of Cardiovascular and Thoracic Surgery, Örebro University hospital.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gupta, Anil
    Dept of Anesthesiology and Intensive Care, Örebro University hospital.
    Tydén, Hans
    Dept of Cardiovascular and Thoracic Surgery, Örebro University hospital.
    Wouters, Patrick
    Dept of Anesthesiology, University hospital Ghent, Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Milrinone and levosimendan during porcine myocardial ischemia: no effects on calcium overload and metabolism2013In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 57, no 6, p. 719-728Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Although inotropic stimulation is considered harmful in the presence of myocardial ischaemia, both calcium sensitisers and phosphodiesterase inhibitors may offer cardioprotection. We hypothesise that these cardioprotective effects are related to an acute alteration of myocardial metabolism. We studied in vivo effects of milrinone and levosimendan on calcium overload and ischaemic markers using left ventricular microdialysis in pigs with acute myocardial ischaemia.

    METHODS: Anaesthetised juvenile pigs, average weight 36 kg, were randomised to one of three intravenous treatment groups: milrinone 50 μg/kg bolus plus infusion 0.5 μg/kg/min (n = 7), levosimendan 24 μg/kg plus infusion 0.2 μg/kg/min (n = 7), or placebo (n = 6) for 60 min prior to and during a 45 min acute regional coronary occlusion. Systemic and myocardial haemodynamics were assessed, and microdialysis was performed with catheters positioned in the left ventricular wall. (45) Ca(2+) was included in the microperfusate in order to assess local calcium uptake into myocardial cells. The microdialysate was analysed for glucose, lactate, pyruvate, glycerol, and for (45) Ca(2+) recovery.

    RESULTS: During ischaemia, there were no differences in microdialysate-measured parameters between control animals and milrinone- or levosimendan-treated groups. In the pre-ischaemic period, arterial blood pressure decreased in all groups while myocardial oxygen consumption remained stable.

    CONCLUSIONS: These findings reject the hypothesis of an immediate energy-conserving effect of milrinone and levosimendan during acute myocardial ischaemia. On the other hand, the data show that inotropic support with milrinone and levosimendan does not worsen the metabolic parameters that were measured in the ischaemic myocardium.

  • 34.
    Bader, Sam Er
    et al.
    Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Brorsson, Camilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Löfgren, N.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Löfgren, F.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, P.-J.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Sundström, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Öman, Mikael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Olivecrona, M.
    Department of Neurosurgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Cerebral haemodynamics and intracranial pressure during haemorrhagic shock and resuscitation with total endovascular balloon occlusion of the aorta in an animal model2024In: European Journal of Trauma and Emergency Surgery, ISSN 1863-9933, E-ISSN 1863-9941Article in journal (Refereed)
    Abstract [en]

    Purpose: To assess changes of cerebral haemodynamic and intracranial pressure (ICP) in animals, with or without elevated ICP, during controlled haemorrhagic shock and resuscitation with Total REBOA (tREBOA).

    Method: In 22 anaesthetized and normoventilated pigs, after placement of catheters for monitoring invasive proximal blood pressure (pMAP), ICP, and vital parameters, and 60 min stabilisation phase, a controlled haemorrhagic shock (HS), was conducted. In 11 pigs (EICPG), an elevated ICP of 25–30 mmHg at the end HS was achieved by simulating an epidural mass. In 11 pigs (NICPG), the ICP was normal. tREBOA was then applied for 120 min. The changes of pMAP and ICP were followed, and cerebral perfusion pressure (CPP) calculated. The integrity of the autoregulation was estimated using a calculated Modified-Long Pressure Reactivity Index (mL-PRx).

    Results: After stabilisation, hemodynamics and physiological parameters were similar and normal in both groups. At the end of the HS, ICP was 16 mmHg in NICPG vs. 32 in EICPG (p = 0.0010). CPP was 30 mmHg in NICPG vs. 6 mmHg in EICPG (p = 0.0254). After aorta occlusion CPP increased immediately in both groups reaching after 15 min up to104 mmHg in NICPG vs. 126 mmHg in EICPG. Cerebrovascular reactivity seems to be altered during bleeding and occlusion phases in both groups with positive mL-PRx. The alteration was more pronounced in EICPG, but reversible in both groups.

    Conclusion: tREBOA is lifesaving by restoration the cerebral circulation defined as CPP in animals with HS with normal or elevated ICP. Despite the observation of short episodes of cerebral autoregulation impairment during the occlusion, mainly in EICPG, tREBOA seems to be an effective tool for improving cerebral perfusion in HS that extends the crucial early window sometimes known as the “golden hour” for resuscitation even after a traumatic brain injury.

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  • 35. Bergquist, Maria
    et al.
    Samuelsson, Line
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Larsson, Anders
    Tydén, Jonas
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Joakim
    Lipcsey, Miklos
    TNFR1, TNFR2, neutrophil gelatinase-associated lipocalin and heparin binding protein in identifying sepsis and predicting outcome in an intensive care cohort2020In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, no 1, article id 15350Article in journal (Refereed)
    Abstract [en]

    To date no biomarkers can aid diagnosing sepsis with adequate accuracy. We set out to assess the ability of Tumor necrosis factor receptor (TNFR) 1 and 2, Neutrophil gelatinase-associated lipocalin (NGAL) and Heparin binding protein (HBP) to discriminate sepsis from non-infected critically ill patients in a large ICU cohort, and to evaluate their value to predict mortality at 30 days. Adult patients admitted to the ICU with an arterial catheter were included. Clinical data and blood samples were prospectively recorded daily. Diagnoses were set retrospectively. Descriptive statistics and logistic regression models were used. NGAL, TNFR1 and TNFR2 were higher in sepsis patients compared to other diagnoses, as well as in non-survivors compared to survivors. In addition, these biomarkers increased with increasing stages of acute kidney injury. TNFR1 and TNFR2 performed similarly to NGAL and CRP in identifying sepsis patients, but they performed better than CRP in predicting 30-day mortality in this ICU cohort. Thus, TNFR1 and TNFR2 may be particularly useful in identifying high risk sepsis patients and facilitate relevant health care actions in this group of sepsis patients.

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  • 36.
    Bergström, Alexandra
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Interhospitala transporter till endovaskulär behandling vid akut ischemisk stroke: En kohortanalys från norra Sverige2021Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 37.
    Bertilsson, Sandra
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Mortalitet och vårdbehov hos patienter med dialyskrävande njursvikt efter hjärtkirurgi2015Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 38.
    Birnefeld, Johan
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Neurosciences.
    Petersson, Karl
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eklund, Anders
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Birnefeld, Elin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Qvarlander, Sara
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Neurosciences.
    Zarrinkoob, Laleh
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Cerebral blood flow assessed with phase-contrast magnetic resonance imaging during blood pressure changes with noradrenaline and labetalol: a trial in healthy volunteers 2024In: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175, Vol. 140, no 4, p. 669-678Article in journal (Refereed)
    Abstract [en]

    Background: Adequate cerebral perfusion is central during general anesthesia. However, perfusion is not readily measured bedside. Clinicians currently rely mainly on MAP as a surrogate even though the relationship between blood pressure and cerebral blood flow is not well understood. The aim of this study was to apply phase contrast MRI to characterize blood flow responses in healthy volunteers to commonly used pharmacological agents that increase or decrease arterial blood pressure.

    Methods: Eighteen healthy volunteers aged 30-50 years were investigated with phase contrast MRI. Intraarterial blood pressure monitoring was used. First, intravenous noradrenaline was administered to a target MAP of 20% above baseline. After a wash-out period, intravenous labetalol was given to a target MAP of 15% below baseline. Cerebral blood flow was measured using phase contrast MRI and defined as the sum of flow in the internal carotid arteries and vertebral arteries. CO was defined as the flow in the ascending aorta.

    Baseline median cerebral blood flow was 772 ml/min (interquartile range, 674 to 871), and CO was 5,874 ml/min (5,199 to 6,355). The median dose of noradrenaline was 0.17 µg · kg−1 · h−1 (0.14 to 0.22). During noradrenaline infusion, cerebral blood flow decreased to 705 ml/min (606 to 748; P = 0.001), and CO decreased to 4,995 ml/min (4,705 to 5,635; P = 0.01). A median dose of labetalol was 120 mg (118 to 150). After labetalol boluses, cerebral blood flow was unchanged at 769 ml/min (734 to 900; P = 0.68). CO increased to 6,413 ml/min (6,056 to 7,464; P = 0.03).

    Conclusion: In healthy awake subjects, increasing MAP using intravenous noradrenaline decreased cerebral blood flow and CO. This data does not support inducing hypertension with noradrenaline to increase cerebral blood flow. Cerebral blood flow was unchanged when decreasing MAP using labetalol.

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  • 39.
    Bjornestad, Elin Eb
    et al.
    Kirurgisk serviceklinikk, Klinikkoverlege, Helse Bergen HF, Norway.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    An obstetric anaesthetist: A key to successful conversion of epidural analgesia to surgical anaesthesia for caesarean delivery?2020In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 64, no 2, p. 142-144Article in journal (Refereed)
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  • 40.
    Björklin, Josefin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    The effect of spinal anaesthesia in postoperative analgesia after caesarean sections - comparison between adjuvant morphine and fentanyl2017Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 41.
    Björkström, Viktor
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology. Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Extracellulärt ATP hos COVID-19-patienter2021Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 42.
    Björsell, Tove
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Department of Infectious Diseases, Karlstad Hospital, Karlstad, Sweden; Centre for Clinical Research and Education, Region Värmland, Karlstad, Sweden.
    Sundh, Josefin
    Department of Respiratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Lange, Anna
    Department of Infectious Diseases, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Forsell, Mattias N. E.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Tevell, Staffan
    Department of Infectious Diseases, Karlstad Hospital, Karlstad, Sweden; Centre for Clinical Research and Education, Region Värmland, Karlstad, Sweden; Faculty of Medicine and Health, School of Medical Sciences, Örebro University, Örebro, Sweden.
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Edin, Alicia
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Normark, Johan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Cajander, Sara
    Department of Infectious Diseases, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Risk factors for impaired respiratory function post COVID-19: a prospective cohort study of nonhospitalized and hospitalized patients2023In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 293, no 5, p. 600-614Article in journal (Refereed)
    Abstract [en]

    Background: Severe COVID-19 increases the risk for long-term respiratory impairment, but data after mild COVID-19 are scarce. Our aims were to determine risk factors for reduced respiratory function 3–6 months after COVID-19 infection and to investigate if reduced respiratory function would relate to impairment of exercise performance and breathlessness. Methods: Patients with COVID-19 were enrolled at the University Hospitals of Umeå and Örebro, and Karlstad Central Hospital, Sweden. Disease severity was defined as mild (nonhospitalized), moderate (hospitalized with or without oxygen treatment), and severe (intensive care). Spirometry, including diffusion capacity (DLCO), was performed 3–6 months after hospital discharge or study enrollment (for nonhospitalized patients). Breathlessness (defined as ≥1 according to the modified Medical Research Council scale) and functional exercise capacity (1-min sit-to-stand test; 1-MSTST) were assessed. Results: Between April 2020 and May 2021, 337 patients were enrolled in the study. Forced vital capacity and DLCO were significantly lower in patients with severe COVID-19. Among hospitalized patients, 20% had reduced DLCO, versus 4% in nonhospitalized. Breathlessness was found in 40.6% of the participants and was associated with impaired DLCO. A pathological desaturation or heart rate response was observed in 17% of participants during the 1-MSTST. However, this response was not associated with reduced DLCO. Conclusion: Reduced DLCO was the major respiratory impairment 3–6 months following COVID-19, with hospitalization as the most important risk factor. The lack of association between impaired DLCO and pathological physiological responses to exertion suggests that these physiological responses are not primarily related to decreased lung function.

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  • 43.
    Blank, Johanna
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Illamående och kräkning efter utskrivning (PDNV) hos dagkirurgiska patienter med låg risk för PDNV – en observationsstudie2019Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 44. Blind, P. -J
    et al.
    Kral, Josef
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wang, Wanzhong
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Kralova, Ivana
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Microdialysis in early detection of temporary pancreatic ischemia in a porcine model2012In: European Surgical Research, ISSN 0014-312X, E-ISSN 1421-9921, Vol. 49, no 3-4, p. 113-120Article in journal (Refereed)
    Abstract [en]

    Background: Ischemic injury to the pancreas occurs in various clinical conditions. A method for online monitoring of pathophysiological events in pancreatic parenchyma is missing. Aims: To assess the timing of microdialysis (MD) technique response on temporary changes in pancreatic perfusion, and to evaluate the relationship between MD data and systemic markers of anaerobic metabolism and inflammation. Methods: In anaesthetized normoventilated pigs, MD probes were placed in right (control) and left (ischemic) pancreatic lobes, respectively. Following the clamping of the vessels, ischemia was verified by tissue oxygen tension (PtiO2) measurements. Results: PtiO2 decreased within 20 min after the clamping of the vessels, already returning to baseline levels at the first sampling point after the removal of the clamp. MD lactate levels increased, whereas pyruvate and glucose levels decreased at 20 min after the induction of ischemia. These trends continued until the end of ischemia and returned to baseline following reperfusion. Serum lactate, amylase and tumor necrosis factor-alpha levels decreased throughout the protocol time. Conclusion: MD data were in concordance with changes in PtiO2, which is indicative of local anaerobic metabolism. MD allowed the detection of pathophysiological processes within the ischemic pancreas at a stage when no elevations of systemic markers of ischemia or inflammation were observed.

  • 45.
    Blom, Mikaela
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Tidigt postoperativt illamående och kräkning efterlaparoskopisk kolecystektomi2022Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 46.
    Boström, Petrus
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Svensson, Johan
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Brorsson, Camilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Rutegård, Martin
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Early postoperative pain as a marker of anastomotic leakage in colorectal cancer surgery2021In: International Journal of Colorectal Disease, ISSN 0179-1958, E-ISSN 1432-1262, Vol. 36, no 9, p. 1955-1963Article in journal (Refereed)
    Abstract [en]

    Purpose: Even though anastomotic leakage after colorectal surgery is a major clinical problem in need of a timely diagnosis, early indicators of leakage have been insufficiently studied. We therefore conducted a population-based observational study to determine whether the patient’s early postoperative pain is an independent marker of anastomotic leakage.

    Methods: By combining the Swedish Colorectal Cancer Registry and the Swedish Perioperative Registry, we retrieved prospectively collected data on 3084 patients who underwent anastomotic colorectal surgery for cancer in 2014–2017. Postoperative pain, measured with the numerical rating scale (NRS), was considered exposure, while anastomotic leakage and reoperation due to leakage were outcomes. We performed logistic regression to evaluate associations, estimating odds ratios (ORs) and 95% confidence intervals (CIs), while multiple imputation was used to handle missing data.

    Results: In total, 189 patients suffered from anastomotic leakage, of whom 121 patients also needed a reoperation due to leakage. Moderate or severe postoperative pain (NRS 4–10) was associated with an increased risk of anastomotic leakage (OR 1.69, 95% CI 1.21–2.38), as well as reoperation (OR 2.17, 95% CI 1.41–3.32). Severe pain (NRS 8–10) was more strongly related to leakage (OR 2.38, 95% CI 1.44–3.93). These associations were confirmed in multivariable analyses and when reoperation due to leakage was used as an outcome.

    Conclusion: In this population-based retrospective study on prospectively collected data, increased pain in the post-anaesthesia care unit is an independent marker of anastomotic leakage, possibly indicating a need for further diagnostic measures.

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  • 47.
    Boström, Petrus
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Svensson, Johan
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics.
    Brorsson, Camilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Rutegård, Martin
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Early postoperative pain as a predictor of anastomotic leakage in colorectal cancer surgeryManuscript (preprint) (Other academic)
  • 48.
    Bromfalk, Åsa
    Umeå University, Faculty of Medicine, Department of Diagnostics and Intervention. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Intervention for prevention: easing children’s preoperative anxiety2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Preoperative anxiety in children is associated with several adverse outcomes and consequences that can have a negative impact on the perioperative outcome and delay recovery. Anxiety can cause stress-induced cardiorespiratory instability, increased postoperative pain, nausea, emergence delirium, and long-term behavior changes. The ideal premedication for children is still debated. Only a few studies have examined the use of premedication in relation to total intravenous anesthesia (TIVA), and there is also a lack of studies exploring staff’s experiences of premedication. The aim of this thesis was to compare midazolam (a benzodiazepine), clonidine, and dexmedetomidine (a2-agonists) given as premedication to preschool children, regarding anxiety, cardiorespiratory response to sedation, time to postoperative recovery, posthospital negative behavior changes (NBCs), and staff’s experiences of the interventions.

    Methods: In a randomized clinical trial, 90 children aged 2–6 years, scheduled for TIVA and ear, nose, and throat surgery, were randomized to one of three groups, receiving midazolam 0.5 mg/kg, clonidine 4 mg/kg, or dexmedetomidine 2 mg/kg. The children were included at a 200-bed county hospital in northern Sweden and observed with validated tools from the day of surgery until two weeks postoperatively (Studies I–IV). To explore the clinical aspects, we conducted focus group interviews to elicit perioperative staff’s experiences of the studied interventions and analyzed the data with qualitative content analysis (Study V). 

    Results: Midazolam reduced preoperative anxiety and provided perioperative cardiorespiratory stability. Clonidine and dexmedetomidine provided deeper sedation along with a minor decrease in heart rate. Some children, mainly from the clonidine group, awoke during the preoperative preparation, triggering anxiety, while the midazolam group remained conscious, calm, and cooperative. Postoperatively, the midazolam group emerged earlier from anesthesia compared to the two a2-agonist groups. However, the midazolam group had more episodes of postoperative anxiety, delirium, and pain compared to both groups receiving a2-agonists, and the overall recovery and discharge time from the post-anesthesia care unit was thus the same for all groups. The posthospital study showed at least one NBC in half of the children during the first two weeks after surgery. The staff’s experiences of premedication could be summarized in three themes: a matter of time, covering the efforts of building trust along with timing the administration and onset; don’t wake the sleeping bear, covering the challenge of maintaining sleep in the sleeping child in order to avoid a backlash if woken; and on responsive tiptoes, covering safety precautions and ethical perspectives on the interventions.

    Conclusion: The different premedications varied in their ability to reduce anxiety and to induce sleep, and this manifested itself throughout the perioperative process. Short-acting midazolam reduced preoperative anxiety but did not provide adequate sleep, and early postoperative emergence occasionally caused a rise in adverse symptom intensification. The long-lasting and sleep-inducing a2-agonists showed an unsatisfactory anxiolytic effect in comparison to midazolam. The sleep was superficial, and an awakening risked triggering anxiety. The staff strove to keep the sedated child asleep, and the recovery time was better and more peaceful when the children slept for a long time postoperatively. However, despite a calm perioperative process, one in two children presented with posthospital NBC. At the doses used in this study, all these premedications seem to be safe in cardiorespiratory terms, and the decision of which one to use should be tailored by individual and time.

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  • 49.
    Bromfalk, Åsa
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Engström, Åsa
    Department of Health, Education and Technology, Division of Nursing and Medical Technology, Luleå University of Technology, Sweden.
    Walldén, Jakob
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Posthospital negative behavioural changes in children: a secondary analysis of a previous randomized clinical trial including a narrative reviewManuscript (preprint) (Other academic)
  • 50.
    Bromfalk, Åsa
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Engström, Åsa
    Luleå Tekniska universitet.
    Walldén, Jakob
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Postoperative recovery in preschool-aged children: A secondary analysis of a randomized controlled trial comparing premedication with midazolam, clonidine, and dexmedetomidine2023In: Pediatric Anaesthesia, ISSN 1155-5645, E-ISSN 1460-9592, Vol. 33, no 11, p. 962-972Article in journal (Refereed)
    Abstract [en]

    Background: Preoperative anxiety in pediatric patients can worsen postoperative outcomes and delay discharge. Drugs aimed at reducing preoperative anxiety and facilitating postoperative recovery are available; however, their effects on postoperative recovery from propofol-remifentanil anesthesia have not been studied in preschool-aged children. Thus, we aimed to investigate the effects of three sedative premedications on postoperative recovery from total intravenous anesthesia in children aged 2–6 years.

    Methods: In this prespecified secondary analysis of a double-blinded randomized trial, 90 children scheduled for ear, nose, and throat surgery were randomized (1:1:1) to receive sedative premedication: oral midazolam 0.5 mg/kg, oral clonidine 4 μg/kg, or intranasal dexmedetomidine 2 μg/kg. Using validated instruments, outcome measures including time for readiness to discharge from the postoperative care unit, postoperative sedation, emergence delirium, anxiety, pain, and nausea/vomiting were measured.

    Results: After excluding eight children due to drug refusal or deviation from the protocol, 82 children were included in this study. No differences were found between the groups in terms of median time [interquartile range] to readiness for discharge (midazolam, 90 min [48]; clonidine, 80 min [46]; dexmedetomidine 100.5 min [42]). Compared to the midazolam group, logistic regression with a mixed model and repeated measures approach found no differences in sedation, less emergence delirium, and less pain in the dexmedetomidine group, and less anxiety in both clonidine and dexmedetomidine groups.

    Conclusions: No statistical difference was observed in the postoperative recovery times between the premedication regimens. Compared with midazolam, dexmedetomidine was favorable in reducing both emergence delirium and pain in the postoperative care unit, and both clonidine and dexmedetomidine reduced anxiety in the postoperative care unit. Our results indicated that premedication with α2-agonists had a better recovery profile than short-acting benzodiazepines; although the overall recovery time in the postoperative care unit was not affected.

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